Multistage air compressors commonly utilize intercoolers between compression stages, in order to cool the compressed air prior to the subsequent compression stage. Many such air compressors utilize a heat exchanger construction whereby the air to be cooled flows over a finned array of tubes having a coolant flowing therethrough. Because the coolant is often water, these constructions are occasionally referred to as water-in-tube (WIT) heat exchangers. Other compressors utilize heat exchangers in which the air flows through tubes having a finned inner surface, and the coolant flows around the tubes. These constructions are referred to as air-in-tube (AIT) heat exchangers. The AIT construction is inherently more compact than the WIT construction, resulting in smaller heat exchanger volume.
A common choice of materials for heat exchangers is aluminum, due in part to its relatively low cost when compared to other materials such as copper. In systems which utilize water as the coolant, however, copper is commonly utilized, due to aluminum's susceptibility to galvanic corrosion. Many conventional WIT heat exchangers flow the water through copper pipes, and thermally couple aluminum fins to the outside of the copper pipes. In AIT heat exchangers, however, the fins must be bonded to inner walls of the tube by a process such as soldering. Due to the fact that there is no practical way to form such a joint between aluminum fins and copper tubes, conventional AIT heat exchangers commonly utilize copper fins. As such, the size advantage of the AIT construction as compared to the WIT construction does not necessarily translate to lower cost, as the material of the WIT is predominantly aluminum, whereas conventional AIT exchangers use copper exclusively. There is thus a need for the unique and inventive heat exchange apparatuses, systems and methods disclosed herein.